package com.itheima.service.impl;

import com.github.pagehelper.PageHelper;
import com.github.pagehelper.PageInfo;
import com.itheima.bean.Student;
import com.itheima.mapper.StudentMapper;
import com.itheima.service.StudentService;
import com.itheima.utils.MyBatisUtils;
import org.apache.ibatis.session.SqlSession;

import java.util.List;

public class StudentServiceImpl implements StudentService {
    @Override
    public PageInfo<Student> selectByPage(Integer currentPage, Integer pageSize) {
        SqlSession sqlSession = MyBatisUtils.getSqlSession();
        StudentMapper studentMapper = sqlSession.getMapper(StudentMapper.class);
        PageHelper.startPage(currentPage,pageSize);
        List<Student> students = studentMapper.selectAll();
        PageInfo<Student> pageInfo = new PageInfo<>(students);
        sqlSession.commit();
        sqlSession.close();
        return  pageInfo;
    }

    @Override
    public void addStu(Student stu) {
        SqlSession sqlSession=null;
        try {
            sqlSession = MyBatisUtils.getSqlSession();
            StudentMapper studentMapper = sqlSession.getMapper(StudentMapper.class);
            studentMapper.addStu(stu);
            sqlSession.commit();
        } catch (Exception e) {
            e.printStackTrace();
            throw new RuntimeException(e);
        } finally {
            if(sqlSession!=null){sqlSession.close();}
        }
    }

    @Override
    public void deleteStu(String num) {
        SqlSession sqlSession=null;
        try {
            sqlSession = MyBatisUtils.getSqlSession();
            StudentMapper studentMapper = sqlSession.getMapper(StudentMapper.class);
            studentMapper.deleteStu(num);
            sqlSession.commit();
        } catch (Exception e) {
            e.printStackTrace();
            throw new RuntimeException(e);
        } finally {
            if(sqlSession!=null){sqlSession.close();}
        }
    }

    @Override
    public void updateStu(Student stu) {
        SqlSession sqlSession=null;
        try {
            sqlSession = MyBatisUtils.getSqlSession();
            StudentMapper studentMapper = sqlSession.getMapper(StudentMapper.class);
            studentMapper.updateStu(stu);
            sqlSession.commit();
        } catch (Exception e) {
            e.printStackTrace();
            throw new RuntimeException(e);
        } finally {
            if(sqlSession!=null){sqlSession.close();}
        }
    }
}
